Useful tips

[Tiller420]

i useful thing that is kinda annoying when using luigi is every so often wave dash backwards and shoot green fire ball.......one of the bset things to do is head butt up tilt headbut then chop them in the air very useful combo and his wavedash to a DS is awsome especial with powered up in the wavedash........and if you ever get lucky if someone is on the edge waiting for you go and taunt by them and watch them die lol

[VilNess]

Umm... that taunt kill works at partyplaying only because its so slow.
Don´t know about your headbutt uptilt combos but sounds quite situational to me. The best followup can be usually only seen by when you see where your opponent DI´s and also considering what char does (s)he play.
That WD backwards and greenball works but it usually won´t get you anywhere. If I occasionally do this I shorthop the fireball to neutralise their aerial attack attemps. This is where luigis fireball actually has some advantages: It goes only horizontally (unless it hits something) and it goes slowly so you can reduce yuor enemys aerial possibilities for awhile.

[Lord_Nikon]

Those combos work with almost everyone, but they are really just depending on the situation. The space animals are really weak towards this combo because of their bad DI ability. Usually, though, this only works till they get a high enough percentage to wiggle recover and n-air or air dodge.

With Luigi, I normally only do one or two u-tilts and then f-air, since, like I said, I only play 4 vs. FFA's, and those combos aren't practical for said matches. The taunt kill is good, because it spikes when somebody is hanging from the ledge, but it's just for fun, not something you can depend on.